BIOCHEMISTRY [PACOP Violet] 1. What biomolecules are considered the most abundant and functionally diverse in the living system? A. Proteins B. Carbohydrates C. Nucleic acid D. Fatty acid E. Terpenoids 2. Which of the following statements is correct about protein structure? I. The primary structure of a protein involves alpha-helics, beta-sheets and other types of folding patterns that occur due to a regular repeating pattern of hydrogen bond formation. II. The secondary structure consist of the amino acids sequence along the chain. III. The tertiary structure involves electrostatic and hydrophobic interations, van der waals interaction, and hydrogen and disulfide bonds, IV. Quaternary structure refers to the interaction of one or more subunits to form a functional protein, using the same force that stabilize the tertiary structure. A. I only B. I and II C. II and III D. I and IV E. III and IV 3. Accumulated misfolded proteins occur in variety of disease. Which of the following proteins is misfolded in patients with Alzheimer’s disease? A. Prion protein B. Alpha-synuclein C.Glutamine stretches D. Beta-amyloid E. None of these 4. Hemoglobinopathies result from mutations that produce alterations in the structure of hemoglobin. One common mutation result is sickle cell anemia, in which a mutated form of hemoglobin distorts the RBC into a crescent shape at low oxygen levels. Sickle cell anemia happens when: A. Valine is being substituted by glutamine at codon number 6 B. Glutamic acid is being substituted by valine at position number 6 C. Glutamine is intercalated by histidine at codon number 6 D. Gene transcription is distrupted E. None of these 5. Acid-base disturbances occur under a variety of conditions. Which of the following is the result of hyperventilation due to retention of carbon dioxide in the lungs. A. Respiratory acidosis B. Respiratory alkalosis C. Metabolic acidosis D. Metabolic alkalosis E. Lactic acidosis BIOCHEMISTRY [PACOP Violet] 6. In amino acids, the pH at which the number of positive charges equals the number of negative charge is termed as_______? A. Chirality B. Amphoteric property C. Optical activity D. Isoelectric point E. Zwitterions 7. Molecules that contain an equal number of ionizable groups of opposite charge and that therefore bear no net charge are termed as____________ A. Chirality B. Amphoteric property C. Optical activity D. Isoelectric point E. Zwitterions 8. Problems associated with connective tissues and structural protein are present in a number of disease. In scurvy, hydroxylation of proline residues is decrease and an unstable form of collagen is produced. Bones, teeth, blood vessels and other structures rich in collagen develop abnormally. Bleeding gums and poor wound healing are often observed. Which of the following vitamin deficiencies is associated to scurvy? A. Vitamin C B. Vitamin E C. Vitamin A D. Vitamin D E. Vitamin K 9. Which of the following is true about insulin functions I. Insulin is release form the pancreas when blood glucose levels are elevated II. Insulin promotes the transport of glucose into muscle and fat cells III. Insulin promotes the storage of energy IV. Insulin increases glycogen catabolism in the liver and muscles A. I and II B. I, II and III C. I, II and IV D. I only E. I, II, III, and IV 10. The enzyme kinetics can be described by what equation? A. Noyes-Whitney Equations B. Henderson- Hasselbach Equation C. Arrhenius Equation D. Van Slyke Equation E. Michaelis-Menten Equation BIOCHEMISTRY [PACOP Violet] 11. Evaluate the given statements. (1) Competitive inhibitors compete with the substrate for binding at the allosteric site of the enzyme. (2) Noncompetitive inhibitors bind to the enzyme or the enzyme substrate complex at the active site. A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 12. In phenylketonuria, the enzyme phenylalanine hydroxylase is deficient. Which of the following statements is not true about the condition? A. Phenylketonuria happens as a result of accumulated phenylalanine in the body B. Tyrosine becomes a essential amino acid among phenylketonuric patients C. Aspartame is recommended for phenylkotenuric patients D. Phenylalanine non metabolism leads to mental retardation. E. None of these 13. Which of the following is not a basic amino acid? A. Histidine B. Leucine C. Lysine D. Arginine E. None of these 14. What are the amide linkages between the alpha-carbonyl group of one amino acid and alpha amino group of another? A. Peptide bonds B. Disulfide bonds C. Hydrogen bonds D. Hydrophobic bonds E. Ionic bonds 15. Edman’s reagent is used to label the amino-terminal residue under mildly alkaline conditions. What is the component of this reagent? A. Monosodium glutamate B. Alpha-naphthol C. Picric acid D. Phenylisothiocyanate E. None of these BIOCHEMISTRY [PACOP Violet] 16. Several different polypeptide helices are found in nature, but the alpha-helix is the most common. What bond stabilizes this helix? A. Hydrogen bond B. Peptide bond C. Phosphodiester bond D. Hydrophobic bond E. Ionic bond 17. What protein structures reverse the direction of a polypeptide chain, helping it form a compact, globular shape? A. alpha-helices B. beta-sheets C. Beta-bends D. All of these E. Ionic bond 18. What specialized group of proteins are required for the proper folding of many species of proteins? A. Chaperones B. Heat shock proteins C. Beta bends D. A and B E. A and C 19. Many proteins consist of a single polypeptide chain, and are defined as monomeric proteins. However, others may consist of two or more polypeptide chains that may be structurally identical or totally unrelated. These statements describe what protein structure? A. Primary structure B. Secondary structure C. Tertiary structure D. Quaternary structure E. None of these 20. What protein is misfolded in Creutzfeldt-Jakob disease? A. Prion B. Glutamine stretches C. Beta-globin D. Beta-amyloid E. None of these 21. What are the two most abundant hemeproteins in humans? A. Hemoglobin and myogobin B. Hemoglobin and cytochrome oxidase C. Hemoglobin and catalase D. Cytochrome and catalase E. All of these BIOCHEMISTRY [PACOP Violet] 22. The complex of protoporphyrin IX and ferrous iron is termed as ___? A. Heme B. Hemoglobin C. Transferin D. Ferritin E. Myoglobin 23. What is the hemeprotein found in heart and skeletal muscles which functions both as a reservoir for oxygen and as an oxygen carrier that increases the rate of transport of oxygen within the muscle cell? A. Hemoglobin B. Myoglobin C. Actin D. Myosin E. Keratin 24. This is found exclusively in red blood cells (RBCs) where its main function is to transport oxygen (O2) from the lungs to the capillaries of the tissues. A. Myoglobin B. Keratin C. Collagen D. Hemoglobin E. Myosin 25. The major hemoglobin in adults compromising of four polypeptide chains held together by noncovalent interactions. A. Hemoglobin A B. Hemoglobin T C. Hemoglobin R D. Hemoglobin F E. Hemoglobin C 26. These are hereditary hemolytic disease in which an imbalance occurs in the synthesis of globin chains. A. Sickle cell anemia B. Thalassemia C. Microcytic anemia D. Iron deficiency anemia E. Hyperchromic anemia 27. Oxidation of the heme component of hemoglobin to the ferric ion (Fe3+) state forms: A. Carboxyhemoglobin B. Methemoglobin C. Ferritin D. Transferrin E. Porphyrin BIOCHEMISTRY [PACOP Violet] 28. Collagen and elastin are examples of: A. Fibrous proteins B. Globular proteins C. Albumins D. Metalloproteins E. Enzymes 29. What is the most abundant protein in the human body? A. Keratin B. Elastin C. Collagen D. Hemoglobin E. Myoglobin 30. Fibril-forming collagen, EXCEPT: A. Type I B. TYPE II C. Type III D. Type IV E. None of these 31. Which of the following pairs is correct about collagen types? A. type I: Fibril associated collagen B. Type II: Network forming collagen C. Type III: Fibril-forming collagen D. Type IV: Fibril forming collagen E. Type IX: Network forming collagen 32. Collagen is rich in ___ and ___, both of which are important in the formation of the triple-stranded helix. A. Proline and leucine B. Proline and isoleucine C. Proline and glycine D. Proline and histamine E. Proline and tyrosine 33. A heterogenous group of generalized connective tissues disorders that result from inheritable defects in the metabolism of fibrillar collagen molecules, and can result from a deficiency of collagen processing enzymes (for example, lysyl hydroxylase or procollagen peptidase), or from mutations in the amino acids sequences of collagen types I, III or V. A. Ehlers-Danlos syndrome B. Von Gierke’s syndrome C. Osteogenesis imperfect D. Huntington’s disease E. Hurler’s syndrome BIOCHEMISTRY [PACOP Violet] 34. A connective tissue protein with rubber like properties in tissues such as the lung. A. Collagen B. Keratin C. Elastin D. Albumin E. Hemoglobin 35. A connective tissue disorder that characterize by impaired structural integrity in the skeleton, the eye, and the cardiovascular system. A. Hurler’s disease B. Marfan syndrome C. Rheumatoid arthritis D. Gaucher’s disease E. Huntington’s disease 36. Lactate to pyruvate conversion is possible due to the presence of lactic dehydrogenase. What enzyme category does lactic dehydrogenase belong? A. Hydrolase B. Oxidoreductase C. Transferases D. Lyases E. Isomerases 37. Which of the following pairs is incorrect about the intracellular location of the biochemical pathways? A. Lysosome: Macromolecular degradation B. Nucleus: Protein synthesis C. Cytosol: Glycolysis D. Mitochondria: Fatty acid oxidation E. Cytosol: HMG shunt 38. What is the process of recycling protein into their constituent amino acid, for reuse by the cell? A. Protein catabolism B. Protein turnover C. Protein synthesis D. Protein denaturation E. Protein degradation 39. A large protein that may contain two or more regions of the polypeptide chain that individual individually have a compact folded structure is called ______. A. Domains B. Chaperones C. Residues D. Proteasome E. None of these BIOCHEMISTRY [PACOP Violet] 40. The following are true about amino acid, EXCEPT: A. They may polymerized to form polypeptides B. They serve as precursors for other small biomolecules C. They may be oxidized to serve as an energy source for the cell D. They act as building blocks of fatty acids E. None of these 41. Of the 20 important amino acids, which is considered optically active? A. Proline B. Lysine C. Arginine D. Leucine E. Glycine 42. The following amino acids contain sulfur on their structure, EXCEPT: A. Cysteine B. Methionine C. Tyrosine D. A and B E. B and C 43. Which of the following amino acids does not contain benzene ring on its structure? A. Tyrosine B. Phenylalanine C. Trytophan D. All of these E. None of these 44. RNAs with catalytic activity are called A. Apoenzymes B. Zymogens C. Proenzymes D. Ribozymes E. Holoenzymes 45. The number of molecules of substrate converted to product per enzyme molecule per second A. Bloom strength B. Turnover number C. Saponification number D. Conformational change E. None of these BIOCHEMISTRY [PACOP Violet] 46. Which of the following is incorrectly paired? A. Holoenzyme: active enzyme B. Apoenzyme: inactive enzyme C. Cofactor: inorganic molecule D. Coenzyme: Small organic molecule E. Prosthetic group: transiently associated with the enzyme 47. Which of the following is false about the kinetic order of enzyme? A. When the substrate concentration [S] is much lesser than the Km, the rate of reaction is first order. B. When [S] is much greater than Km, the velocity is constant and equal to Vmax. C. When [S] is much less than Km, the velocity of the reaction is approximately proportional to the substrate concentration. D. When the substrate concentration [S] is greater than the Km, the rate of reaction is zero order. E. None of these 48. Irreversible inhibitors bind to enzymes through what bond? A. Covalent bond B. Ionic bond C. Hydrogen bond D. Hydrophobic bond E. Sigma and pie bonds 49. Which of the following is true about competitive inhibitions? A. The reaction of the substrate and inhibitor is irreversible B. Substrate binds to active site, inhibitor binds to allosteric site C. Inhibitor is covalently bonded to the enzyme D. The reaction is not surmountable E. None of these 50. This occurs when inhibitor and substrate bind at different site on the enzyme. A. Competitive inhibition B. Non-competitive inhibition C. Functional inhibition D. Chemical inhibition E. Physiological inhibition 51. Enzyme are often measured in clinical diagnosis. Which of the following is correlated to an elevated alanine aminotransferase? A. Brain tumor B. Hepatic damage C. Prostate cancer D. Colon cancer E. Eye injury BIOCHEMISTRY [PACOP Violet] 52. ADH requires NAD+ for catalytic activity. In the reaction catalyzed by ADH, an alcohol is oxidized to an aldehyde as NAD+ is reduced and dissociates from the enzyme. The NAD+ is functioning as a (an): A. Apoenzyme B. Coenzyme-cosubstrate C. coenzyme-prosthetic group D. cofactor E. Eye injury 53. Which of the following is not true about the digestion of protein? A. Protein digestion begins in the mouth B. The digestion of protein may be due gastric acid secretion C. Pancreatic enzyme aid in the digestion of protein D. Aminopeptidases digest oligopeptides in the small intestine E. None of these 54. What is most common genetic error of amino acid transport? A. Phenylketonuria B. Alkaptonuria C. Cystinuria D. Methemoglobinemia E. Pellagra 55. A disease of malabsorption resulting from immune-mediated damage to the small intestine in the response to ingestion of gluten A. Cystic fibrosis B. Celiac disease C. Ulcerative disease D. Crohn’s disease E. Conn’s disease 56. What is the first step in the catabolism of most amino acids? A. Conjugation B. Transamination C. Transpetidation D. Hydrolysis E. Reduction 57. All amino acids participate in transamination at some point in their catabolism, EXCEPT: A. Lysine B. Threonine C. Trytophan D. A and B E. A and C BIOCHEMISTRY [PACOP Violet] 58. What is the only amino acid that undergoes rapid oxidative deamination? A. Lysine B. Tyrosine C. Glutamate D. Trytophan E. Ornithine 59. In the transport of ammonia from the peripheral tissues to the liver, which of the following mechanism is true? A. Glutamine is transported in the blood to the liver where it is cleaved by glutaminase to produce glutamate and free ammonia B. Alanine is transported by the blood to the liver, where it is converted to pyruvate by transamination C. Transamination of pyruvate to alanine is required to allow transport of alanine to the liver. D. A and B E. All of these 60. Where is the production and excretion site? A. Liver for production, kidney for excretion B. Muscle for production, kidney for excretion C. Liver for production, mammary gland for excretion D. Liver for both production and excretion E. None of these 61. What amino acid is the immediate precursor of both ammonia and aspartate nitrogen? A. Glutamate B. Aspartate C. Pyruvate D. Oxaloacetate E. Lactate 62. The synthesis of urea is located on which cell site? A. Mitochondria B. Cytosol C. DNA D. A and B C. All of these 63. Ammonia is produced by all tissues during the metabolism of a variety of compounds. However, the level of ammonia in the blood must be kept very low, because even slightly elevated concentrations (Hyperammonemia) are toxic to what part of the body system? A. Autonomic nervous system B. Central nervous system C. Integumentary system D. Skeletal system E. Digestive system BIOCHEMISTRY [PACOP Violet] 64. The following are potential sources of ammonia, EXEPT A. Glutamine B. Monoamines C. Purines D. Pyrimidines E. Resorcinol 65. What two nitrogen-containing compounds are incorporated in the urea cycle? A. Alanine and glutamate B. Glutamine and alanine C. Aspartate and ammonia D. Ammonia and aspartate E. Alanine and arginine 66. Evaluate the two statements: (1) Essential amino acids must be obtained from diet in order for normal protein synthesis to occur. (2) Essential amino acids are produced from the intermediates of metabolism of protein. A. Only 1 is correct B. Only 2 is correct C. Both are correct D. Both are incorrect 67. Amino acids whose catabolism yields either acetoacetate or one of its precursors (Acetyl CoA or acetoacetyl CoA) are termed as A. Glucogenic amino acids B. Ketogenic amino acids C. Metabotropic compounds D. Amphoteric amino acids E. Zwitterionic amino acids 68. Which of the following amino acids does not belong to the group? A. Tyrosine B. Isoleucine C. Phenylalanine D. Lysine E. Tryptophan 69. The amino acids leucine, isoleucine and valine are: A. Branched-chain amino acids B. Essential amino acids C. Aromatic amino acids D. A and B E. C and D BIOCHEMISTRY [PACOP Violet] 70. Succinyl CoA, a Kreb’s cycle intermediate may be derived from the degradation of the following, EXCEPT A. Valine B. Isoleucine C. Theonine D. Asparagine E. None of these 71. The most common clinically encountered inborn error of amino acid metabolism A. Tyrosinemia type I B. Phenylketonuria C. Albinism D. Maple syrup urine disease E. Pellagra 72. Tyrosine is needed in the synthesis of the following, EXCEPT: A. Tissue protein B. Melanin C. Catecholamines D. Fumarate E. Phenylacetate 73. The following are clinical characteristics of classical phenylketonuria: A. Elevated phenylalanine B. CNS symptoms C. Hypopigmentation D. Blue eyes E. All of these 74. A disease which is characteristic by feeding problems, vomiting, dehydration, severe metabolic acidosis. This condition is due to partial or complete deficiency in the branched-chain alpha-keto acid dehydrogenase. A. Phenylketonuria B. Maple syrup urine disease C. Pellagra D. Albinism E. Hypopigmentation 75. Albinism refers to a group of conditions in which a defect in tyrosine metabolism results in a deficiency in the production of A. Melatonin B. Melanin C. Melanocyte D. All of these E. None of these BIOCHEMISTRY [PACOP Violet] 76. The homocystinurias are a group of disorders involving defects in the metabolism of homocysteine. The most common cause of homocystinuria is a defect in the enzyme cystathionine beta-synthase. Patients can be responsive (or nonresponsive) to oral administration of vitamin coenzyme of cystathionine beta-synthase. What vitamin is referred to in this condition? A. Thiamine B. Niacin C. Pantothenic acid D. Pyridoxine E. Biotin 77. Which of the following amino acid should be avoided of by patients with alkaptonuria? A. Phenylalanine B. Tyrosine C. Alanine D. A and B E. B and C 78. Which of the following pairs (precursor 🡪 product) is incorrect? A. Histidine 🡪 histamine B. Trytophan 🡪 serotonin C. Arginine 🡪 nitric oxide D. Methionine 🡪 purine/pyrimidine E. Tyrosine 🡪 dopamine 79. Which one of the following statements concerning a 1-week-old male infant with undetected classic phenylketonuria is correct? A. Tyrosine is a nonessential amino acid for the infant B. High levels of phenylpyruvate appear in his urine C. Therapy must begin within the first year of life D. A diet devoid of phenylalanine should be initiated immediately E. When the infant reaches adulthood, it is recommended that diet therapy be discontinued 80. The structure of porphyrin is shown below. Which cyclic organic molecule is present on the structure? A. Indole B. Pyrrole C. Quinolone D. Pyridine E. Piperidine 81. The most prevalent metalloporphyrin in humans is heme. It serves as a prosthetic group for: A. Cytochrome B. Hemoglobin C. Peroxidase D. All of these E. A and B BIOCHEMISTRY [PACOP Violet] 82. Inherited (or occasionally acquired) defect is heme synthesis may result to: A. Porphyria B. Phenylketonuria C. Methemoglobinemia D. Lead poisoning E. Albinism 83. What is the approximate number of days of red blood cells to be in the circulation before degradation? A. 40 days B. 80 days C. 120 days D. 150 days E. 365 days 84. Bilirubin and biliverdin are examples of: A. Bile salts B. Bile pigments C. Bile duct D. All of these E. None of these 85. Certain anionic drugs, such as salicylates and sulfonamides, can displace bilirubin from albumin, permitting bilirubin to enter the central nervous system. This causes the potential for neural damage in infants known as: A. Saint Louis Encephalitis B. Systemic Lupus Erythematosus C. Steven-Johnson’s syndrome D. Kernicterus E. All of these 86. Van den Bergh reaction determines the concentration of: A. Protein B. Bilirubin C. Heme D. Glucose E. Cholesterol 87. The following are Catecholamines, EXCEPT: A. Epinephrine B. Norepinephrine C. Acetylcholine D. Dopamine E. None of these BIOCHEMISTRY [PACOP Violet] 88. What organic polymer protects underlying cell from the harmful effects of sunlight? A. Melanin B. Keratin C. Collagen D. Catecholamines E. Heme 89. The 4D symptoms of pellagra include: diarrhea, dermatitis, dementia and death. This is due to the deficiency of: A. Niacin B. Tyrosine C. Trytophan D. A and C E. A and B 90. Trytophan I. One-letter representation is “T” II. Non-polar molecule III. Deficiency of which can cause Hartup disease IV. The structure contains phenol side chain A. I & II are correct B. I,II, and III are correct C. II and III are correct D. I,II,III and IV are correct E.I,II,III and IV incorrect 91. What is the isoelectric point (pl) of arginine? A. 7.87 B. 5.55 C. 10.75 D. 7.3 E. 11.8 92. Estimate the isoelectic point of the structure (reaction mechanism) given below. A. 2 B. 9 C. 6 D. 5 E. 7 BIOCHEMISTRY [PACOP Violet] 93. Which of the following secondary derived proteins have highest molecular weight characteristic? A. Proteoses B. Peptones C. Peptides D.A and B E. B and C 94. Tyrosine can be detected by: A. Xanthoproteic test B. Millon’s test C. Sakaguchi test D. A, B and C E. A and B 95. Hopkin’s Cole reaction gives positive result in: A. Gelatin B. Collagen C. Tryptophan D. A and B E. B and C 96. Which of the following is an essential amino acid in man? A. Tyrosine B. Proline C. Aspartate D. Threonine E. Serine 97. Which of the following amino acids is NOT basic? A. Lysine B. Arginine C. Ornithine D. Glutamine E. Histidine 98. Which of the following bonds is not affected by denaturation due to its high stability? A. Disulfide bond B. Peptide bond C. Hydrogen bond D. Ionic bond E. None of these BIOCHEMISTRY [PACOP Violet] 99. Arginine and histidine are: A. Essential amino acid B. Non-essential amino acid C. Semi-essential amino acid D. Acidic amino acid E. Aromatic amino acid 100. A tripeptide involved in cellular oxidation-reduction, and is required for maintaining the integrity of RBC and lens of eyes. A. Glutathione B. Vasopressin C. Encephalin D. Oxytocin E. Retinol 101. Which of the following is true about the central dogma of molecular biology? A. The genetic information found in DNA is copied and transmitted to daughter cells through DNA replication. B. Transcription is involved in RNA synthesis C. The code contained in the nucleotide sequence of messenger RNA molecules is translated to complete gene expression. D. All of these E. A and B 102. Which of the following not true about DNA structure? A. Phosphodiester bonds stabilize the DNA structure B. In the double helix, the chains are paired in a parallel manner C. Uracil is always paired with a thymine and a cytosine is always paired with a guanine D. A and B E. B and C 103. A rule which states that "in any sample of DNA, the amount of adenine equals the amount of thymine, the amount of guanine equals the amount of cytosine, and the total amount of purines equals the total amount of pyrimidines.” A. Zaitsev’s rule B. Hund’s rule C. VSEPR rule D. Chargaff’s rule E. Markovnikov’s rule 104. Which of the following structural forms of DNA is right handed? A. B-DNA B. Z-DNA C. A-DNA D. A and B E. A and C BIOCHEMISTRY [PACOP Violet] 105. Most species of bacteria also contain small, circular, extrachromosomal DNA molecules called plasmids, which may carry genes that convey A. Antibiotic resistance B. Antibacterial effect C. Mutagenic effect D Antigenicity E. Transcription 106. When the two strands of the DNA double helix are separated, each can serve as a template for the replication of a new complementary strand. This produces two daughter molecules, each of which contains two DNA strands with an antiparallel orientation. This describes: A. Conservative replication B. Semiconservative replication C. Dispersive replication D. Antigenicity E. Transcription 107. Human topoisomerase II is targeted by: A. Etoposide B. Ciprofloxacin C. Penicillin D. Vancomycin E. Chloramphenicol 108. The strand that is being copied in the direction away from the replication fork, and is synthesize discontinuously, with small fragments of DNA being copied near the replication fork. A. Leading strand B. Lagging strand C. RNA primer D. Single strand E. Double strand 109. Which of the following rRNA size particles is not present in prokaryotes? A. 23S B. 15S C. 5S D. 40S E. 50S 110. Which nitrogenous base is not present in RNA structure? A. Cytosine B. Uracil C. Thymine D. Adenine E. Guanine BIOCHEMISTRY [PACOP Violet] 111. Ribonucleotides contains: A. Ribose B. Nitrogenous base C. Phosphate D. All of these E. None of these 112. Which of the consequence of point mutation is expected to happen in the codon transition of UCA to UCU? Use the genetic code table below for your reference. A. Silent mutation B. Missense mutation C. Nonsense mutation D. Spontaneous mutation E. Frameshift mutation 113. A hereditary disease that primarily affects the pulmonary and digestive systems, most commonly caused by deletion of three nucleotides from the coding region of a gene, resulting in the loss of phenylalanine at the 508th position in the protein encoded by that gene. A. Cystic fibrosis B. Crohn’s disease C. H. pylori infection D. Ulcerative colitis E. Chronic obstructive pulmonary disease 114. This states that the first (5’) base of the anticodon is not as spatially defined as the other two bases. Movement of that first base allows nontraditional base-pairing with the last (3’) base of the codon, thus allowing a single tRNA to recognize more than one codon for a specific amino acid A. Chargaff’s rule B. Wobble hypothesis C. Shine-Dalgamo sequence D. Semiconservative E. Chronic obstructive pulmonary disease 115. Many antimicrobials inhibit protein translation. Which of the following antimicrobials is correctly paired with is mechanism of action? A. Tetracyclines – inhibits peptidyltransferase B. Diphtheria toxin – binds to the 30S subunits C. Puromycin – inactivates EF-2 D. Erythromycin – binds with 50S ribosomal subunits E. Clindamycin – binds to the 30S ribosomal subunits BIOCHEMISTRY [PACOP Violet] 116. The movement of the uncharged tRNA from the P to the E site (before being released), and movement of the peptidyl-tRNA from the A to the P site is termed as: A. Transcription B. Translation C. Translocation D. Transformation E. Transferin 117. Thymine structure B. 118. In DNA double helix, which of the following is not true? A. Guanine base pairs with cytosine B. Adenine on one chain forms a base pair with uracil on the other chain C. The chains are antiparallel D. Each DNA molecule is composed of two polynucleotide chain joined by hydrogen bonds between bases E. The double-stranded molecule is twisted to form a helix with major and minor grooves 119. Which of the following statements regarding DNA denaturation is incorrect? A. Alkali can cause DNA breakage B. Heat can cause DNA separation C. Heat and alkali can break phosphodiester bonds D. A and B E. All of these 120. In DNA replication, what enzyme acts to prevent the extreme supercoiling of the parental helix that would result as consequence of unwinding at a replication fork? A. Topoisomerase B. RNA polymerase C. Helicases D. Isomerases E. Proteolytic enzymes 121. Phase of eukaryotic cell cycle involving DNA (replication) synthesis A. G1 phase B. G2 phase C. G0 phase D. S phase E. M phase BIOCHEMISTRY [PACOP Violet] 122. The deficiency results in an inability to salvage hypoxanthine or guanine, from which excessive amounts of uric acid are produced A. Hurler syndrome/ B. Sanfilippo syndrome C. Gaucher’s disease D. Lesch-Nyhan syndrome E. Forbes’ disease 123. Uric acid A. May be derived from hypoxanthine B. May be derived from guanine C. The end product of protein metabolism D. A and B E. A, B and C 124. What ribosomal tRNA acts as a binding site of an incoming aminoacyl-tRNA? A. E site B. P site C. A site D. A and C are correct E. B and C are correct 125. Where is the cellular location of ribosomes? A. Cytosol B. Rough endoplasmic reticulum C. Smooth endoplasmic reticulum D. A and B E. B and C 126. A rare hereditary defect of the enzyme system where the cells cannot repair the damage DNA, resulting in extensive accumulation of mutation and, consequently, early and numerous skin cancers. A. Basal cell carcinoma B. Psoriasis C. Xeroderma pigmentosum D. Necrotizing fasciitis E. Lepromatous leprosy 127. Which of the following statements best describes carbohydrates? A. Least abundant organic molecules in nature B. Provide a significant fraction of the dietary calories for most organisms C. Structural component of many organisms D. All of these E. B and C BIOCHEMISTRY [PACOP Violet] 128. Which of the following is not a disaccharide? A. Sucrose B. Trehalose C. Cellobiose D. Mannose E. Lactose 129. Which of the following are isomers? A. Fructose and glucose B. Glucose and mannose C. Mannose and galactose D. All of these E. A and C 130. The D- and an L-sugar designation of monosaccharide are: A. Tautomers B. Enantiomers C. Monomers D. Epimers E. Anomers 131. Alpha-D-glucopyranose and beta-D-glucopyranose are: A. Enantiomers B. Diasteromers C. Anomers D. A and C E. B and C 132. Which of the following polysaccharides is/are derived from plant sources? A. Cellulose B. Glycogen C. Starch D. All choices are correct E. A and C 133. Which of the following is not true about lactose? A. Reducing sugar B. With alpha-1,4 glycosidic linkage C. Contains fructose and galactose D. A and B E. B and C BIOCHEMISTRY [PACOP Violet] 134. The final product of carbohydrate digestion is: A. Glucose B. Galactose C. Fructose D. All of these E. A and B 135. Which of the following statements is true? I. Digestion of carbohydrates begins in the mouth II. Further digestion of carbohydrate by pancreatic enzyme can occur on the small intestine III. Final carbohydrate digestion by enzymes synthesized by the intestinal mucosa cells A. I only B. II only C. III only D. I and II E. I, II and III 136. Lactose intolerance is present among: A. Lactase-deficient people B. Sucrase-deficient people C. Isomaltase-deficient people D. All of these E. None of these 137. Disaccharides, oligosaccharides and polysaccharides contain monomer sugar units which are linked by what bond? A. Hydrogen bond B. Phosphodiester bond C. Glycosidic bond D. Disulfide bond E. Hydrophobic bond 138. Which of the following statements best describes glucose? A. It is a ketose and usually exists as a furanose ring B. It is a C-4 epimer of galactose C. It is utilized in biological systems only in the L-isometric form D. It is a product from dietary starch by the action of alpha-amylase E. Homopolysaccharides of glucose, formed by the action of glycosyltransferase, are always branched molecules that contain only beta-glycosidic linkages BIOCHEMISTRY [PACOP Violet] 139. Clinitest is a nonspecific test that produce a change in color if urine is positive for reducing substances. Which of the following sugars is not detected by this test? A. Xylulose B. Fructose C. Sucrose D. Galactose E. Glucose 140. What effect should drugs like acarbose and miglitol have on the digestion of lactose? A. Lactose intolerant B. Diarrhea C. Lactose digestion D. A and B E. None of these 141. Catabolic reaction I. Breakdown of complex molecules II. Exergonic reactions III. Exemplified by glycolysis and glycogenolysis A. I only B. I and II C. I and III D. I, II and III E. II and III 142. Evaluate the two statements: (I) Pyruvate is the end product of glycolysis in cells with mitochondria and an adequate supply of oxygen. (II) The conversion of glucose to lactate is called anaerobic glycolysis because it can occur without the participation of oxygen. A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 143. The enzyme that may add or remove phosphate group of sugar is called: A. Hexokinase B. PFK C. Pyruvate kinase D. All of these E. A and C 144. The enzyme that function as a glucose sensor in the maintenance of blood glucose homeostasis. A. Glucokinase B. Hexokinase D C. Fructokinase D. A and B E. All of these BIOCHEMISTRY [PACOP Violet] 145. Glucose-6-phosphate to fructose-6-phosphate conversion requires: A. Isomerization B. Carbon removal C. Water removal D. Carbon division E. A and C 146. Cleavage of fructose 1,6-biphosphate is made by: A. Hexokinase B. Aldolase C. Enolase D. Isomerase E. Pyruvate kinase 147. Which of the following involves oxidation-reduction reaction? A. Glyceraldehyde 3-phosphate to 1,3-biphosphoglycerate B. PEP to pyruvate C. Glucose to glucose 6-phosphate D. DHA to glyceraldehydes E. Glucose-6-phosphate to fructose-6-phosphate 148. The kinase enzyme in glycolysis are physiologically reversible, EXCEPT: A. Hexokinase B. Type IV hexokinase C. Pyruvate kinase D. Phosphoglycerate kinase E. Phosphofructokinase 149. In glycolysis, what is the role of phosphoglycerate mutase? A. Shift of the phosphate group from carbon 3 to carbon 2 B. Dehydration of 2-phosphoglycerate C. Formation of pyruvate producing ATP D. Oxidation of glyceraldehyde 3 –phosphate E. Isomerization of dihydroxyacetone phosphate 150. What is the second most common cause of enzyme deficiency related non-spherocytic hemolytic anemia? A. Pyruvate dehydrogenase deficiency B. Glucose 6-phosphate dehydrogenase deficiency C. Morquio syndrome D. Pyruvate kinase deficiency E. Sickle cell anemia BIOCHEMISTRY [PACOP Violet] 151. Anaerobic glycolysis: I. Pyruvate is the end product II. Generates 2 ATP per glucose III. Produces 1 NADH A. Only I is correct B. Only II is correct C. Only III is correct D. I and III are correct E. I, II and III are correct 152. What is the major fuel for the TCA cycle? A. Pyruvate B. Acetyl CoA C. PEP D. Lactate E. Oaloacetate 153. A person in a fasting state has I. Increase of blood glucose II. Increase of release of glucagon III. Decrease of insulin A. I only B. I and II C. II and III D. III only E. I, II and III 154. What is the final pathway where the oxidative metabolism of carbohydrates, amino acids and fatty acids take place? A. Kreb’s cycle B. Glycolysis C. Urea cycle D. HMP shunt E. Oxidative phosphorylation 155. Aldol condensation of acetyl CoA and oxaloacetate yields A. Citrate B. Isocitrate C. Fumarate D. Malate E. Succinate BIOCHEMISTRY [PACOP Violet] 156. The conversion of citrate to isocitrate requires A. Dehydroganase B. Aconitase C. Fumarase D. Aldolase E. Kinase 157. How much NADH are produced in TCA cycle? A. 1 NADH B. 2 NADH C. 3 NADH D. 12 NADH E. 6-8 NADH 158. How many ATP molecules are produced from the oxidation of one molecule of acetyl CoA? A. 6-8 ATPs B. 12 ATPs C. 24 ATPs D. 36-38 ATPs E. 129 ATPs 159. Which of the following reactions produce NADH? A. Oxidation and decarboxylation of isocitrate B. Oxidative decarboxylation of a-ketoglutarate C. Oxidation of Malate D. A and B E. All of these 160. In Kreb’s cycle, how many NADH, FADH2 and GTP are produced in one round of cycle? A. 2 NADH, 2 FADH2, and 2 GTP B. 1 NADH, 3 FADH2, and 3 GTP C. 3 NADH, 1 FADH2, and 1 GTP D. 3 NADH, 2 FADH2. and 1 GTP E. 4 NADH, 0 FADH2, and 2 GTP 161. Oxidation of acetyl CoA yields A. Carbon dioxide B. Water C. Glucose D. A and B E. A and C BIOCHEMISTRY [PACOP Violet] 162. The lactic acid cycle is also known as: A. Kreb’s cycle B. Gluconeogenesis C. Cori’s cycle D. Urea cycle E. Water cycle 163. Which of the following may serve as precursor for gluconeogenesis? A. Lactate B. Glycerol C. Glucogenic amino acid D. A and C E. All of these 164. Seven glycolytic reactions are reversible and are used in the synthesis of glucose from lactate or pyruvate. In gluconeogenesis, however, some reactions are irreversible and must be circumvented by alternate reactions that are energetically favor the synthesis of glucose. This gluconeogenesis reactions include: I. Carboxylation of pyruvate II. Decarboxylation of oxaloacetate III. Dephosphorylation of fructose 1,6-bisphosphate IV. Dephosphorylation of glucose 6-phosphate A. I and II B. I and III C. I, II, and III D. I, II, III, and IV E. II, III, and IV 165. The synthesis of glucose from pyruvate by gluconeogenesis: A. Occurs exclusively in the cytosol B. In inhibited by an elevated level of glucagon C. Requires participation of biotin D. Involves lactate as an intermediate E. Requires the oxidation/reduction of FAD 166. Which one of the following reactions is unique to gluconeogenesis? A. Lactate → Pyruvate B. Phosphoenolpyruvate → pyruvate C. Oxaloacetate → phosphoenolpyruvate D. Glucose 6-phosphate → fructose 6-phosphate E. 1,3-bis-phosphoglycerate → 3-phosphoglycerate BIOCHEMISTRY [PACOP Violet] 167. The main stores of glycogen in the body are found in the: A. Skeletal muscle B. Liver C. Kidney D. A and B E. B and C 168. Glycogen is a branched-chain polysaccharide made exclusively from a-D-glucose. Glucose units are mainly linked by: A. α(1→4) Linkage B. α(1→6) Linkage C. β(1→4) Linkage D. A and B E. B and C 169. Evaluate the two statements (1) Glycogenesis is synthesis of glycogen (2) Glycolysis is degradation of glycogen. A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 170. Evaluate the two statements: (1) Glycogenesis accelerates during periods when the body has been well fed (2) Glycogenesis accelerates during periods of fasting. A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 171. An elevated insulin level results in: I. Increased glycogenesis II. Decreased glycogenesis III. Elevated glucagon (or epinephrine) A. I only B. I and II C. I and III D. II and III E. I, II and III 172. Pompe’s disease is A. Lysosomal storage disease B. Glycogen storage disease C. Type II GSD D. All of these E. B and C BIOCHEMISTRY [PACOP Violet] 173. Increased ingestion of glucose leads to: I. Increased blood glucose II. Increased glucagon III. Decreased insulin A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 174. A deficiency of the phosphatase causes glycogen storage disease Type 1a. This disease results in an inability of the liver to provide free glucose to the body during a fast. A. Von Gierke’s disease B. Pompe’s disease C. Cori’s disease D. Anderson’s disease E. McArdle’s disease 175. Which of the following pairs is incorrect? A. Type 1b GSD: Cori’s disease B. Type II GSD: Pompe’s disease C. Type III GSD: Cori’s disease D. Type V: McArdle’s disease E. Type VI: Her’s disease 176. The most common monosaccharide consumed by humans: A. Glucose B. Fructose C. Ribose D. Mannose E. Arabinose 177. High-fructose corn syrup typically contains: A. 90% fructose and 10% galactose B. 55% fructose and 45% glucose C. 90% fructose and 10% glucose D. 50% fructose and 50% glucose E. 55% galactose and 45% glucose 178. What enzyme is deficient from essential fructosuria? A. Fructokinase B. Aldolase A C. Aldolase B D. Aldolase C E. Hexokinase BIOCHEMISTRY [PACOP Violet] 179. What is the major carbohydrate energy source of sperm cells? A. Glucose B. Sorbitol C. Ribose D. Fructose E. Mannose 180. Galactose I. Major dietary source is milk II. C-2 epimer with glucose III. Detected by mucic acid test A. I only B. I and II C. I and III D. II and III E. I, II and III 181. Following the intravenous injection of lactose into a rat, none of the lactose is metabolized. However, ingestion of lactose leads to rapid metabolism of this disaccharide. The difference in these observations is a result of: A. Presence of lactose in the serum B. The absence of hepatic galactokinase C. The absence of maltase in the serum. D. The presence of lactase in the intestine E. None of these 182. Pentose Phosphate Pathway A. Hexose monophosphate pathway B. 6-phosphogluconate pathway C. Occurs in cytosol D. All choices are correct E. A and C 183. An inherited disease characterized by hemolytic anemia cause by the inability to detoxify oxidizing agents. A. Glucose 6-phosphate dehydrogenase deficiency B. Glucose 6-phosphate deficiency C. Gaucher’s disease D. Krabbe’s disease E. Glycogen storage disease BIOCHEMISTRY [PACOP Violet] 184. In preparation for a trip to an area of India where malaria is epidemic, a young man is given primaquine prophylactically. Soon thereafter, He develops a hemolytic condition. The most likely cause of the hemolysis is a less-than-normal level of which of the following? A. Glucose 6-phosphate B. Oxidized form of NAD C. Reduced form of glutathione D. Ribose 5-phosphate E. Ribulose 5-phosphate 185. These are long, unbranched, hetero polysaccharide chains generally composed of a repeating disaccharide unit. A. Glycoproteins B. Glycosaminoglycans C. Metaloproteins D. Lipopolysaccharides E. Carbohydrates 186. The most abundant glycosaminoglycans (GAGs) in the body A. Chondroitin sulfate B. Keratin sulfates C. Hyaluronic acid D. Dermatan sulfates E. Heparin 187. Which of the following pairs is correct about mucopolysaccharidoses (MPS)? A. Hurler syndrome: MPS I B. Hunter syndrome: MPS II C. Sly syndrome: MPS III D. A and B E. B and C 188. Mucopolysaccharidoses are inherited lysosomal storage diseases. They are caused by: A. An increased rate of synthesis of the carbohydrate component of proteoglycans B. The synthesis of polysaccharides with an altered structure. C. Defects in the degradation of GAGs in the proteoglycans D. The synthesis of abnormally small amounts of protein cones E. An insufficient of proteolytic enzymes 189. Which of the following is a cellular defense against reactive oxygen species (ROS)? A. Superoxide dismutase B. Catalase C. Glutathione peroxidase D. A and B E. A, B and C BIOCHEMISTRY [PACOP Violet] 190. Evaluate the two statements (1) Conversion of FMN to FMNH2 requires oxidation (2) Conversion of NADH to NAD+ requires reduction. A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect 191. A theory that explains how the free energy generated by the transport of electricity by the electron transport chain is used to produce ATP from ADP + Pi A. Chemiosmotic theory B. Mitchell hypothesis C. Archimedes law D. Noyes-Whitney equation E. A and B 192. In electron transport train, the transport (“pumping”) of protons (H+) across the inner mitochondria membrane from the matrix to the intermembrane space does not happen at: A. Complex I B. Complex II C. Complex III D. Complex IV E. A and C 193. Leber hereditary optic neuropathy is an example of A. Mitochondrial mutation B. Nuclear mutation C. Ribosomal mutation D. Cytosolic mutation E. Oxidative mutation 194. Adenosine Triphosphate I. Contains the base adenine, the sugar ribose, and three phosphate groups joined each other by two anhydride bonds II. Produced from adenosine diphosphate (ADP) and inorganic phosphate (Pi) mainly by the process of substrate phosphorylation. III. Plays a central role in energy exchanges in your body A. Only I is correct B. Only II is correct C. I and II are correct D. I and II are incorrect E. I, II and III BIOCHEMISTRY [PACOP Violet] 195. NADH and/or FADH2 are produced by: A. Glycolysis B. TCA cycle C. β-oxidation of fatty acids D. A and B E. All of these 196. Which of the following complexes is incorrectly paired? A. Complex I: NADH dehydrogenase complex B. Complex II: Succinate dehydrogenase C. Complex III: cytochrome b-c1 complex D. Complex IV: cytochrome oxidase E. Complex V: ADP synthase 197. For each pair of electrons that enters the chain from NADH, how many protons are pumped out of the mitochondria? A. 10 protons B. 6 protons C. 8 protons D. 12 protons E. 24 protons 198. In electron transport chain, which complex is blocked by either carbon monoxide or cyanide? A. Complex I B. Complex II C. Complex III D. Complex IV E. Complex V 199. A leading cause of blindness, which is due to, overtime, oxidative damage to the retinal pigment epithelium, such that the brain no longer processes light correctly. A. Macular degeneration B. Astigmatism C. Diplopia D. Nearsightedness E. Farsightedness 200. The following are non-enzymatic antioxidants (free-radical scavengers), EXCEPT: A. Vitamin E B. Vitamin C C. Carotenoids D. Flavonoids E. Vitamin K BIOCHEMISTRY [PACOP Violet] 201. The most potent ROS A. Hydrogen peroxide B. Hydroxyl radical C. Superoxide D. Coenzyme Q E. Nitric oxide 202. Metformin is the standard fist-line oral medication for type 2 diabetes. The use of the drug has the potential side effect of lactic acidosis. Which of the following explains why this lactic acid buildup is rarely seen clinically? A. The red blood cells utilize the lactate as fuel. B. The renal cell utilizes the lactate as fuel C. The cardiac muscle cells utilize the lactate as fuel. D. The large, voluntary muscle groups utilize the lactate as fuel. E. The lactate directly enters the TCA cycle to be oxidized. 203. A contestant on a TV reality show, in which the contestant had to survive off the land for an extended period of time, developed recurrent diarrhea, dermatitis and had trouble remembering things. These symptoms could be brought about due to lack of which one of the following in the contestant’s diet? A. Niacin B. Thiamine C. Riboflavin D. Vitamin C E. Vitamin D 204. The following contains glucose, EXCEPT: A. Glycogen B. Triacylglycerol C. Glycoprotein D. Glycolipid E. Ceramide 205. Lipid are: I. Water-insoluble organic molecules II. Can be extracted from tissues by polar solvent III. Major source of energy for the body A. I only B. I and II C. II and III D. I and III E. I, II and III 206. Which of the following is true with regard to digestion of biomolecules? A. Protein digestion starts in the mouth B. Carbohydrate digestion begins in the stomach C. Lipid digestion begins in the stomach D. A and B E. B and C BIOCHEMISTRY [PACOP Violet] 207. What anti-obesity agent inhibits both gastric and pancreatic lipases? A. Colestipol B. Simvastatin C. Orlistat D. Niacin E. Gemfibrozil 208. Which hormone/s control/s lipid digestion? I. Insulin II. Incretin III. Secretin IV. Cholecystokinin A. I and II only B. II and III only C. III and IV only D. I, II and III E. I, II, III and IV 209. These are disk-shaped clusters of amphipathic lipids that coalesce with their hydrophobic groups on the inside and their hydrophilic groups on the outside. A. Micelles B. Aggregates C. Coalesces D. Chylomicron E. Liposomes 210. A rare, autosomal recessive disorder cause by a deficiency of lipoprotein lipase resulting to chylomicronemia and hypertriacylglycerolemia. A. Type I hyperlipoproteinemia B. Type IIa familial hypercholesterolemia C. Familial dysbetalipoproteinemia D. Familial hypertriglyceridemia E. Tangier disease 211. Which of the following fatty acids is a dietary essential in normal humans? A. Linolenic acid B. Linoleic acid C. Arachidonic acid D. A and B E. B and C 212. Which of the following contains omega-3 on its structure? A. Linolenic acid B. Linoleic acid C. Arachidonic acid D. Palmitic acid E. Arachidic acid BIOCHEMISTRY [PACOP Violet] 213. A teenager, concerned about his weight, attempts to maintain a fat-free diet for a period of several weeks. If his ability to synthesize various lipids were examined, he would be found to be most deficient in his ability to synthesize: A. Triacylglycerol B. Phospholipids C. Cholesterol D. Sphingolipids E. Prostaglandins 214. The oxidation of a molecule of palmitoyl CoA to CO 2 and H2O produces: A. 8 acetyl CoA, 7 NADH and 7 FADH2 B. 16 acetyl CoA, 16 NADH and 16 FADH2 C. 7 acetyl CoA, 8 NADH and 8 FADH2 D. 8 acetyl CoA, 8 NADH and 8 FADH2 E. 7 acetyl CoA, 7 NADH and 7 FADH2 215. The major supplier of NADPH for fatty acid synthesis: A. HMP shunt B. Pentose phosphate pathway C. Electron transport chain D. A and B E. A, B and C 216. Destruction of fatty acid chain happens in the: A. Ribosome B. Smooth endoplasmic reticulum C. Nucleus D. Cytoplasm E. Mitochondrion 217. Evaluate the two statements: (1) if a species of acylglycerol is solid at room temperature, it is called a “fat” (2) if liquid, it is called an “oil”. A. Only 1 is correct B. Only 2 is correct C. Both 1 and 2 are correct D. Both 1 and 2 are incorrect 218. The yield from the complete oxidation of fatty acids to CO2 and H2O A. 9 kcal/g B. 4kcal/g C. 7.1kcal/g D. 3.4 kcal/g E. None of these BIOCHEMISTRY [PACOP Violet] 219. The most common inborn error of fatty acid oxidation A. Medium chain fatty acyl CoA dehydrogenase (MCAD) deficiency B. Carnitine deficiency C. Methylmalonyl CoA mutase deficiency D. Zellweger syndrome E. X-linked adrenoleukodystrophy 220. Acetoacetate, 3-hydroxybutyrate, and acetone are example of: A. Ketone bodies B. Ketogenic amino acids C. Glucogenic amino acids D. Ketose sugar E. Aldose sugar 221. Excessive production of ketone bodies in diabetes mellitus leads to: A. Ketonemia B. Ketonuria C. Ketoacidosis D. A and B E. A, B and C 222. Phospholipids I. Amphipathic II. Have hydrophilic bond III. Have a hydrophobic tail A. Only I is correct B. I and II are correct C. I, II and III are correct D. Only III is correct E. I, II and III are correct 223. Phospholipids that contain glycerol are called: A. Glycerophospholipids B. Phosphoglycerides C. Glycealdehydes D. Glycerin phosphate E. A and B 224. Which of the following is correctly paired? I. Serine + PA → phosphatidylserine II. Ethanolamine + PA → cephalin III. Choline + PA → lecithin IV. Inositol + PA → phosphatidylinositol A. I and IV B. I and II C. II and III BIOCHEMISTRY [PACOP Violet] D. I, II and III E. I, II, III, and IV 225. A long chain fatty acid attached to the amino group of sphingosine through an amide linkage is known as: A. Ceramide B. Cerebroside C. Ganglioside D. Sulfatide E. Lipopolysaccharide 226. What is the role of phosphatidylcholine in the lungs? A. Surfactant B. Prevents osmosis C. Antimicrobial D. Neurotransmitter E. All of these 227. Two molecules of phophatidic acid connected by a molecule of glycerol A. Lecithin B. Inositol C. Cardiolipin D. Cephalin E. Phosphatidylethanolamine 228. Glucocorticoids (for example, cortisol) inhibit: A. Phospholipase A1 B. Phospholipase A2 C. Phospholipase C D. Phospholipase D E. Fatty acyl CoA transferase 229. An autosomal recessive disease caused by in the inability to degrade sphingomyelin leading to severe mental retardation and neurodegeneration and death in early childhood. A. Nieman-Pick disease B. Farber’s disease C. Farby’s disease D. Gaucher’s disease E. Tay-sach’s disease 230. Which of the following is not present in lactosylceramide? A. Sphingosine B. Fatty acid C. Glucose C. Galactose E. Ganglioside BIOCHEMISTRY [PACOP Violet] 231. The most common lysosomal storage disease A. Niemann-pick disease B. Farber disease C. Farby’s disease D. Gaucher’s disease E. Tay-sach’s disease 232. The following are eicosanoids, EXCEPT: A. Prostaglandin B. Thromboxanes C. Leukotrienes D. Palmitic acid E. Arachidonic acid 233. Which of the following is correct with regarding prostaglandin? I. Regulate smooth muscle contraction II. Regulate blood vessel diameter III. Mediator of inflammatory response IV. Stimulate gastric acid synthesis A. I only B. I and II C. I, II and III D. I and III E. I, II, III and IV 234. Evaluate the two statement: (1) linolenic acid is a dietary precursor of prostaglandin. (2) arachidonic acid is the immediate precursor of the predominant class of prostaglandin. A. 1 is correct, 2 is incorrect B. 1 is incorrect, 2 correct C. 1 and 2 are correct D. 1 and 2 are incorrect 235. Two isoenzyme of PGH synthase are known. Which is the inducible form? A. COX 1 B. COX 2 C. LOX D. A and B E. A and C 236. Which of the following NSAIDs is a specific inhibitor of COX-2 isoenzyme? A. Aspirin B. Indomethacin C. Phenylbutazone D. Celecoxib E. Mefenamic acid BIOCHEMISTRY [PACOP Violet] 237. Which of the following is correct about leukotrienes? I. Mediators of allergic response and inflammation II. Their synthesis is affected by NSAIDs III. Aspirin-induced asthma is a response to overproduction to leukotrienes with NSAID use A. I and II B. I and III C. III only D. II and III E. I, II, and III 238.The use of celecoxib to increase the risk of: A. Hypertension B. Heart attack C. Kidney failure D. Atherosclerosis E. Diabetes mellitus 239. Aspirin-induced asthma (AIA) is a severe reaction to nonsteroidal anti-inflammatory drugs (NSAIDs) characterized by bronchoconstriction 30 minutes to several hours after ingestion. It is seen in as many as 20% of adults. Which of the following statements best explains the symptoms seen in patients with AIA? A. NSAIDs inhibit the activity of the CFTR protein, resulting in thickened secretion that block airways. B. NSAIDs inhibit COX but not lipoxygenase, resulting in the flow of arachidonic acid to leukotriene synthesis. C. NSAIDs activate the COX activity of PGH synthase, resulting in increased synthesis of prostaglandins that promote vasodilation. D. NSAIDs activate phospholipases, resulting in decreased amounts of dipalmytoylphosphatidylcholine and alveolar collapse. E. NSAIDs inhibit both COX and LOX enzyme and the asthma attack is due to allergic response to various antigens. 240. The following are true about cholesterol, EXCEPT: A. Cholesterol is a structural component of all cell membrane B. Cholesterol is a precursor of bile acids and vitamin C. C. Liver plays a central role in the regulation of the body’s cholesterol homeostasis. D. Cholesterol is the major sterol in animal tissues. E. All of these 241. What is the rate-limiting enzyme and the major control point for cholesterol biosynthesis? A. HMG CoA reductase B. Decarboxylase C. Kinase D. Transferase E. Isomerase BIOCHEMISTRY [PACOP Violet] 242. Cholelithiasis is a: A. Kidney failure condition B. Cholesterol storage disease C. Cholesterol gallstone disease D. Cholesterol degradation failure E. Heart problem 243. A patient with Type 1 hyperlipoproteinemia is deficient in: A. Lipoprotein lipase B. HMG-CoA synthase C. HMG-CoA reductase D. L-carnitine E. Apo B 244. Which of the following lipoproteins contains the highest amount of triacylglycerol? A. Chylomicron B. HDL C. LDL D. VLDL E. IDL 245. A patient with Type II hyperlipidemia is expected to have an increase in: A. LDL B. Cholesterol C. TAG D. A and B E. A, B, and C 246. An increase in plasma HDL is correlated to a/an: A. Decrease risk of artherosclerosis B. Increase risk atherosclerosis C. No significant effect in arthrosclerosis D. Increase chance of CHD E. Increase chance of Tangier disease 247. What precursor is present in glucocorticoids, mineralocorticoids, and sex hormone? A. Monosaccharides B. Prostanioc acid C. Isoprene units D. Cholesterol E. Purine/pyrimidines 248. What hormone is labeled as “stress hormone”? A. TSH B. ACTH C. LH and FH D. Prolactin E. Vasopressin BIOCHEMISTRY [PACOP Violet] 249. Aldosterone’s primary effect: I. Increase glucose uptake II. Increase sodium uptake III. Increase potassium excretion IV. Increase blood pressure A. I and II B. II and III C. II and III D. II, III and IV E. I, II, III and IV 250. Carl Derrick, 35y/o male was seen in the emergency room because of recurrent abdominal pain. The history revealed a 2-year pattern of pain in the upper right quadrant, beginning several hours after the ingestion of meal rich in fried/fatty food. Ultrasonographic examination demonstrated the presence of numerous stones in the gallbladder. The patient initially elected treatment consisting of exogenously supplied chenodeoxycholic acid, but eventually underwent surgery for the removal of the gallbladder, and had a full recovery. The rationale for the initial treatment of this patient with chenodeoxycholic acid is that this compound: A. Interferes with enterohepatic circulation B. Inhibits cholesterol synthesis C. Increases de novo bile acid production D. Increase cholesterol solubility in the bile E. Increase the hydrophobicity of gallstones 251. Which lipoproteins deliver dietary (exogenous) TAG to peripheral tissues? A. HDL B. LDL C. Chylomicron D. VLDL E. IDL 252. Activator of lipoprotein lipase A. Apoprotein CII B. Apoprotein B48 C. Apoprotein A1 D. Apoprotein E E. Apoprotein B100 253. Major carriers of triacylglycerols A. LDL B. VLDL C. Chylomicron D. A and B E. B and C BIOCHEMISTRY [PACOP Violet] 254. The formation of lipid-rich plagues in the intima of arteries A. Gout B. Cornea arcus accumulation C. Atherosclerosis D. Farber’s disease E. Tangler disease 255. In terms of density, arrange the following lipoproteins in descending order: I. Chylomicrons II. LDL III. VLDL IV. IDL V. HDL A. I-II-III-V-IV B. I-III-II-IV-V C. V-IV-III-II-I D. V-II-IV-III-I E. V-I-II-IV-III 256. Patients with Familial lipoprotein lipase (LDL) deficiency (chylomicronemia) is treated with: A. Niacin B. Diet C. Gemfibrozil D. Simvastatin E. Cholestyramine 257. Fatty acids, which are the major source of energy in the human body, are oxidized mainly by: A. Beta-oxidation B. w-oxidation C. a-oxidation D. peroxisomal oxidation E. none of these 258. A patient with high blood cholesterol levels was treated with Lovastatin. This drug lowers blood cholesterol levels due primarily to which one of the following? A. inhibition of absorption of dietary cholesterol B. inhibition of lipoprotein lipase in adipose tissue C. inhibition of citrate lyase in the liver D. inhibition of HMG-CoA reductase in the liver and peripheral tissues E. induction of LDL receptors in the liver and peripheral tissues BIOCHEMISTRY [PACOP Violet] 259. Type 1 diabetes mellitus is caused by a decrease ability of the B-cells of the pancreas to produce insulin. A person with Type 1 diabetes mellitus who has neglected to take insulin injection will exhibits which one of the following? A. Increased fatty acid synthesis from glucose in liver B. Decreased conversion of fatty acids to ketone bodies C. Increased stone of triacylglycerol in adipose tissue D. Increased production of acetone E. Increased glucose transport into muscle cells 260. Shannon, a 2-day-old infant born at 32 weeks gestation has had breathing difficulties since birth and is currently on a respirator and 100% oxygen. These difficulties occur due to which one of the following? A. An inability of the lungs to contract to exhale B. An inability of the lungs to expand when taking in air C. An inability of the lung to respond to insulin D. An inability of the lungs to respond to glucagon E. An inability of the lungs to produce energy 261. Biological effects of insulin: I. Increase glucose uptake II. Increase glycogenolysis III. Increase protein synthesis IV. Increase fat synthesis A. I and II B. I, II and III C. I, III, and IV D. III and IV E. I, II, III and IV 262. Biological effects of glucagon I. Increase glucose uptake II. Increase glycogenolysis III. Increase protein synthesis IV. Increase fat synthesis A. I and II B. I and III C. I, II, and III D. II and III E. I, II, III and IV BIOCHEMISTRY [PACOP Violet] 263. Which of the following oppose/s the many actions of insulin? I. Glucagon II. Epinephrine III. Cortisol IV. Growth hormone A. I and II B. I and III C. I, II and III D. II and III E. I, II, III and IV 264. Which of the following is not considered an essential component of the diet but may provide a significant contribution to the daily caloric intake of some individuals? A. Carbohydrate B. Protein C. Essential fatty acid D. Ethanol E. Minerals 265. Consumption of fats containing w-6 polyunsaturated fatty acid PUFAs: A. Increase HDL levels B. decrease LDL level C. Decrease HDL level D. A and B E. B and C 266. True statement about trans fatty acid include: I. Unsaturated fatty acid II. Elevate serum LDL III. Elevate serum HDL IV. Increase the risk of CHD A. I and II B. I, II and III C. II and III D. I, II and IV E. I, II, III and IV 267. Correct statement about nitrogen balance include: I. Positive nitrogen balance occur when nitrogen intake exceeds nitrogen excretion II. Negative nitrogen balance occurs when nitrogen loses are greater than nitrogen intake. III. Negative nitrogen balance is observed in situations in which tissue growth occurs. IV. Positive nitrogen balance is associated with inadequate dietary protein A. I and II B. II and III C. III and IV D. I, II and III E. I, II, III, and IV BIOCHEMISTRY [PACOP Violet] 268. Given the information that a 70-kg man is consuming a daily average of 275g of carbohydrate, 75g of protein, and 65g of lipid, how many kilocalories are generated? A. 415kcal B. 1,985 kcal C. 3,410 kcal D. 1950 kcal E. 4,310 kcal 269. Where in the body the carotenoids are converted to vitamin A? A. Liver B. Kidney C. Muscles D. Brain E. Intestine 270. Which of the following fat soluble vitamins has a coenzyme function? A. Vitamin A B. Vitamin C C. Vitamin K D. Vitamin D E. Vitamin E 271. Macrocytic nutritional anemia: I. Deficiency in folate II. Deficiency in Vitamin B12 III. Iron deficiency anemia IV. Protein-energy malnutrition A. I and II B. II and III C. III and IV D. I, II and III E. I, II, III and IV 272. A condition in which the blood has a lower than normal concentration of hemoglobin, which results in reduced ability to transport oxygen. A. Anemia B. Hypoxia C. Methemoglobinemia D. Erythropoietic protoporhyria E. Cyanosis 273. What is the most common form of nutritional anemia? A. Iron-deficiency anemia B. Pernicious anemia C. Thallassemia D. Megaloblastic anemia E. Pernicious anemia BIOCHEMISTRY [PACOP Violet] 274. The most common neural tube defect is: A. Spina bifida B. Anencephaly C. Microcephaly D. A and B E. B and C 275. Vitamin B12 is synthesized only by: A. Microorganisms B. Plants C. Animals D. A and B E. B and C 276. Megaloblastic anemia is due to deficiency of: A. Vitamin B9 B. Vitamin B12 C. Vitamin B15 D. A and C E. A and B 277. A severe malabasorption of vitamin B12 leads to A. Pernicious anemia B. Iron deficiency anemia C. Sickle cell anemia D. Aplastic anemia E. Polycythemia vera 278. Vitamin C: I. Active form of vitamin c II. An oxidizing agent III. Coenzyme on hydroxylation reactions IV. Facilitates the absorption of dietary iron A. I and II B. III and IV C. I, II, and III D. I, III and IV E. I, II, III and IV BIOCHEMISTRY [PACOP Violet] 279. Anti-oxidant vitamin include: I. vitamin C II. Vitamin A III. Vitamin D IV. Vitamin E A. I and II B. I and III C. I, II, and III D. I, II and IV E. I, II, III and IV 280. The only water-soluble vitamin with significant toxicity A. Vitamin B1 B. Vitamin C C. Vitamin B6 D. Vitamin B9 E. Vitamin B2 281. Thiamine deficiency with is seen primarily in association with chronic alcoholism A. Beriberi B. Scurvy C. Wernicke-Korsakoff syndrome D. Hemorrhage E. RBC fragility 282. Dermatitis, diarrhea and dementia are classic symptoms of what vitamin deficiency? A. Vitamin B1 B. Vitamin B2 C. Vitamin B3 D. Vitamin B6 E. Vitamin B9 283. Niacin effect on lipids: I. decrease LDL II. Decrease VLDL III. Decrease TAG IV. Decrease HDL A. I and II B. I, II and III C. II, III and IV D. I and III E. I, II, III and IV BIOCHEMISTRY [PACOP Violet] 284. Dermatitis, cheilosis and glossitis are symptoms of which vitamin deficiency? A. Vitamin B1 B. Vitamin B2 C. Vitamin B3 D. Vitamin B4 E. Vitamin B5 285. The addition of raw egg white to the diet as a source of protein induces symptoms of biotin deficiency, namely, dermatitis, glossitis, loss of appetite, and nausea. What component of raw egg white tightly binds biotin and prevents its absorption from the intestine? A. Collagen B. Avidin C. Albumin D. Glianin E. Albuminoid 286. What vitamin is a component of Coenzyme A (CoA), which functions in the transfer of acyl groups? A. Vitamin B1 B. Vitamin B2 C. Vitamin B3 D. Vitamin B5 E. Vitamin B6 287. Which vitamin A forms is useful in dermatology? A. Retinol B. Retinal C. Beta-carotene D. Retinoic acid E. Retinyl ester 288. Isotretinoin I. 13-cis-retinoic acid II. Treatment of promyelocytic leukemia III. Useful in severe, recalcitrant cystic acne A. I only B. II only C. III only D. I and II E. I, II and III 289. Function of vitamin D, EXCEPT: A. Increasing uptake of calcium by the intestine B. Increasing loss of calcium by the kidney C. Stimulating resorption of bone D. A and B E. B and C BIOCHEMISTRY [PACOP Violet] 290. Vitamin K is required in the hepatic synthesis of prothrombin and blood clotting factors II, VII, IX, and X. Which drug antagonizes the action of Vitamin K? A. Aspirin B. Ibuprofen C. Heparin D. Warfarin E. Clopidogrel 291. The least toxic of the fat-soluble vitamins A. Vitamin A B. Vitamin D C. Vitamin C D. Vitamin E E. Vitamin K 292. Vitamin K deficiency is common in: A. Newborn B. Adult male C. Adult female D. Adolescent E. Geriatric patients 293. Vitamin K A. plays an essential role om preventing thrombosis B. increases the coagulation time in newborn infants with hemorrhagic disease C. is present in high concentration in cow or breast milk D. is synthesized by intestinal bacteria E. is a water-soluble vitamin 294. Deficiency of peroximal PhyH (phytanoyl-CoA a-hydroxylase) A. Refsum disease B. Zellweger syndrome C. Trisomy syndrome D. Lysosomal storage disease E. Klinefelter syndrome 295. Which of the following biochemical reactions does not happen in the mitochondria? A. Kreb cycle B. Fatty acid synthesis C. Lipoprotein synthesis D. Beta-oxidation E. Heme synthesis BIOCHEMISTRY [PACOP Violet] 296. People who suffer from binges of overeating, followed by self-induced vomiting to avoid gaining weight have a condition called: A. Anorexia nervosa B. Bulimia C. Stress eating disease D. Anemia E. A and B 297. The observable traits of the individuals produced by the interaction of the genes and the environment A. Phenotype B. Genotype C. Genes D. Allele E. Locus 298. Turner syndrome A. Trisomy 13 B. Trisomy 18 C. Trisomy 21 D. Monosomy X E. XYY 299. The genetic composition of the individual A. Phenotype B. Genotype C. Heritability D. Penetrance E. Variable expressivity 300. Which of the following is correctly paired? I. Point mutations: a change in one bases of the DNA II. Deletions: a loss of bases in the DNA III. Insertions: new DNA sequence added into existing DNA IV. Extra copy of an allele: trisomy for an autosomal chromosome A. I and II B. II and III C. I and IV D. I, II and III E. I, II, III and IV